Qualcomm Incorporated

Song Shi

Lennart Karl-Axel Mathe

Pengfei Li

Iulian Mirea

Yunfei Shi

Joseph Dale Rutkowski

Brett Christopher Walker

Joseph Duncan

Thomas Domenick Marra

Moataz Abdelsamie Abdelfattah

Chi Fan Yung

Mukesh Bansal

Zhiqing Zhang

Jun Hua

Eugene Robert Worley

Ankit Srivastava

Lin Xue

Liang Dai

Jongrit Lerdworatawee

Mingliang Wang

Sally Amin

A method for unbalancing a tri-level switching regulator uses hysteretic control when switching across multiple states of the tri-level switching regulator. The method includes determining a battery voltage and an output voltage of the tri-level switching regulator. The method also includes dynamically adjusting at least one of a first hysteretic window of a first hysteretic comparator associated with a second switching state of the tri-level switching regulator and a second hysteretic window of a second hysteretic comparator associated with a first switching state of the tri-level switching regulator based on the battery voltage and the output voltage.

Hysteretic window adjustment of tri-level switching regulator

An apparatus is disclosed for a single-inductor multiple-output (SIMO) power converter with a cross-regulation switch. An example apparatus includes a power source and a SIMO power converter. The SIMO power converter includes an input node coupled to the power source, a first node, a second node, a ground node, and an inductor coupled between the first node and the second node. The single-inductor multiple-output power converter also includes a first switch coupled between the input node and the first node, a second switch coupled between the first node and the ground node, and a cross-regulation switch coupled between the input node and the second node.

Single-inductor multiple-output (SIMO) power converter with a cross-regulation switch

A tri-level converter provides three levels of power supply to a power amplifier that includes a supply path. The supply path has a first transistor and a first inherent body diode associated with the first transistor, as well as a second transistor and a second inherent body diode associated with the second transistor. A polarity of the second body diode is reversed relative to a polarity of the first body diode. A first driver is configured to drive the first transistor and the first inherent body diode to control a power supply, including a battery supply signal, to an output of the tri-level converter. The tri-level converter is coupled to a switching node.

Multi-level power supply architecture for radio frequency power amplifiers

Certain aspects of the present disclosure provide methods and apparatus for generating an envelope tracking power supply voltage. For example, certain aspects of the present disclosure provide an envelope tracking power supply having a linear amplifier having an output coupled to a power supply node of an amplifier, wherein a power supply node of the linear amplifier is coupled to a first voltage supply node. The envelope tracking power supply may also include a switch mode power supply having an output coupled to the power supply node of the amplifier. Certain aspects also include a circuit having a first switch coupled to the first voltage supply node and a second switch coupled to a second voltage supply node, wherein a power supply node of the switch mode power supply is coupled to the first switch and the second switch.

Selecting between boosted supply and battery supply

Certain aspects of the present disclosure provide methods and apparatus for operating an envelope tracking power supply. The method may include receiving, from a modem of a device, information indicative of a transmit waveform statistic of a signal to be wirelessly transmitted by the device. The method may further include adjusting a configuration of the envelope tracking power supply based on the transmit waveform statistic of the signal.

Adjusting envelope tracking power supply

The present disclosure describes a synchronized switching power supply for a radio frequency (RF) power amplifier. In some aspects, a synchronized power supply circuit comprises a first switch connected between a power rail and a first terminal of an inductor that is connected to an output of the circuit via its second terminal. The circuit also includes a second switch connected between a ground rail and the first terminal of the inductor, and respective gate drivers for the first and second switches. An amplifier of the circuit is connected to the power rail and has an output connected to the output of the circuit. A current sensor is connected between the output of the amplifier and the output of the circuit, with an output of the current sensor being connected to an input of a comparator. A delay circuit is connected between an output of the comparator and the first and second gate drivers, and may synchronize the power supply circuit.

Switching power supply for RF power amplifiers

Techniques for dynamically generating a headroom voltage for an envelope tracking system. In an aspect, an initial headroom voltage is updated when a signal from a power amplifier (PA) indicates that the PA headroom is insufficient. The initial headroom voltage may be updated to an operating headroom voltage that includes the initial voltage plus a deficiency voltage plus a margin. In this manner, the operating headroom voltage may be dynamically selected to minimize power consumption while still ensuring that the PA is linear. In a further aspect, a specific exemplary embodiment of a headroom voltage generator using a counter is described.

Dynamic headroom for envelope tracking

The present disclosure includes envelope tracking circuits and methods with adaptive switching frequency. In one embodiment, a circuit comprising an amplifier to receive an envelope tracking signal having an envelope tracking frequency and output voltage and current to a power supply terminal of a power amplifier circuit. A programmable comparator receives an output signal from the amplifier and generates a switching signal having a switching frequency. A switching regulator stage receives the switching signal and outputs a switching current to the power supply terminal. A frequency comparison circuit configures the programmable comparator based on the envelope tracking frequency and the switching frequency so that the switching frequency tracks the envelope tracking frequency.

Envelope tracking circuits and methods with adaptive switching frequency

Techniques for generating a boost clock signal for a boost converter from a buck converter clock signal, wherein the boost clock signal has a limited frequency range. In an aspect, the boost clock signal has a maximum frequency determined by Vbst/T, wherein Vbst represents the difference between a target output voltage and a battery voltage, and T represents a predetermined cycle duration. The boost converter may include a pulse insertion block to limit the minimum frequency of the boost clock signal, and a dynamic blanking/delay block to limit the maximum frequency of the boost clock signal. Further techniques are disclosed for generally implementing the minimum frequency limiting and maximum frequency limiting blocks.

Programmable frequency range for boost converter clocks

Techniques for preventing reverse current in applications wherein a tracking supply voltage is placed in parallel with a switching power stage. The tracking supply voltage may be boosted to a level higher than a battery supply voltage using, e.g., a boost converter. In an aspect, a negative current detection block is provided to detect negative current flow from the boosted tracking supply voltage to the battery supply voltage. A high-side switch of the switching power stage may be disabled in response to detecting the negative current. To prevent false tripping, the tracking supply voltage may be further compared with the battery supply voltage, and a latch may be provided to further control the high-side switch.

Reverse current prevention

Simple and efficient techniques for closed loop control of a boost converter. In an aspect, a current feed-forward (CFF) mode of operation includes providing current information to a control logic block controlling transistor switches of the boost converter to advantageously smooth the signals present in the closed loop control of the system. In another aspect, a modified peak current (MPC) mode of operation includes providing a simplified control mechanism based on a peak current mode of operation. Both CFF mode and MPC mode may share similar circuit elements, allowing a single implementation to selectively implement either of these modes of control. Further techniques are provided for determining average current information for the logic block.

Control logic for switches coupled to an inductor

Techniques for reducing ringing arising from L-C coupling in a boost converter circuit during a transition from a boost ON state to a boost OFF state. In an aspect, during an OFF state of the boost converter circuit, the size of the high-side switch coupling a boost inductor to the load is gradually increased over time. In this manner, the on-resistance of the high-side switch is decreased from a first value to a second (lower) value over time, which advantageously reduces ringing (due to high quality factor or Q) when initially entering the OFF state, while maintaining low conduction losses during the remainder of the OFF state. Further techniques are provided for implementing the high-side switch as a plurality of parallel-coupled transistors.

Soft turn-off for boost converters

Techniques for creating one or more notch frequencies in the power density spectrum of an output voltage generated by switching circuitry. In an aspect, high- and low-side switches are coupled to an output voltage via an inductor. The spectral power of the output voltage at one or more frequencies is estimated, and the estimated spectral power is provided to a switch controller controlling the switches. The switch controller may be configured to switch the switches only in response to detecting that the estimated spectral power at the notch frequency is at a minimum. In certain exemplary aspects, the techniques may be incorporated in an envelope-tracking system, wherein the switching circuitry forms part of a switched-mode power supply (SMPS) supplying low-frequency power to a power amplifier load.

Noise shaping for switching circuitry

In a particular embodiment, an apparatus includes an electrostatic discharge (ESD) clamping transistor coupled to a ground terminal of a device. The apparatus further includes a switch coupled between a body terminal of the ESD clamping transistor and the around terminal.

Growing community of inventors

San Diego, CA, United States of America

Song Shi